Copying lathe



P 1 948. G. CLAUSING EI'AL 2,449,878

coPYINe LATHE Filed Dec. 27, 1943 4 Sheets-Sheet 1 INVENTORS. GeorgeClausing Charles 5. Gary CLAUSING ETAL 2,449,373

COPYING LATHE 4 Sheets-Sheet 2 Fiied Dec. 27, 1943 IOO- Sept. 21, 1948.G. CLAUSING ET AL 2,449,378

' commie LATHE Filed Dec. 27, 1943 4 Sheets-Sheet 4 Fig." 5, r weINVENTORS.

Geof charfe s a ggg BY Patented Sept. 21, 1948 v v 2,449,878 COPYINGLATHE George. Clausing and Charles B. Gary, Portsmouth, Ohio, assignorsto Vulcan Corporation, Portsmouth, Ohio, a corporation of OhioApplication December 27, 1943, Serial No. 515,704

7 Claims.

This invention relates to copying lathes of the type employed to producethree dimensional objects of irregular form and is particularlyvdirected to improvements therein relating to the means for supportingand moving the model being copied and the work piece relatively andsymmetrically with respect to the coacting model wheel and cutter head.i

To emphasize the features which distinguish the present invention fromexisting apparatus let it be pointed out that in the conventionalreproducing lathe the model and workpiece are supported byand moved in aframe which swings in an arc-determined by its axis of suspension. Suchan arrangement is in some respects satisfactory particularly when themodel and workpiece are arranged in axial alignment. However, thepresent invention is an outstanding improvement not only over thisconventional type of lathe, but for all types of three dimensionalreproducing devices.

The lathe embodying the present invention is provided with a framehaving means for supporting and rotating the model and mean for movingand guiding the frame positively in a lateral direction andsimultaneously maintaining the frame so that all positions are parallelduring its movement. Such motion providing accuracy of operation of thehighest order and also providing for consistent accuracy in allmodifications in'the arrangement of a model and one or more workpieceswithin the frame as will appear in the following detailed description.Briefly the apparatus embodyingthe invention consists of a main framehaving straight ways thereon upon which one or more carriages travel.The carriage is provided with a model wheel arranged to engage the modeland a driven cutter head to engage and shapethe workpiece. Suitablemeans is providedlfor feeding the carriage during the shaping operation.In the embodiments of the invention illustrated, the model and workpieceare pivotally supported with their axes parallel within a frame whichwill hereinafter be called the work frame. v

This frame desirably is rectangular in form and generally thinpresenting a flat structure 13'- ing in a plane. Desirabl but notessentially the work frame is mounted with its flatwise plane in avertical position with the axes of' the model and workpiece situated'oneabove the other within the frame. Suitable means are provided forrotating the model and workpiece in synchronism during the cuttingoperation.

A highly eflicient and novel means is provided for guiding the frame totravel with a motion characterized as bodily movement transversely ofits general fiatwise plane and without angular displacement from thatplane. To produce this motion the four corner portions of therectangular frame are connected by rigid links to a stabilizingmechanism utilizing a pair of rigid torque shafts. The shaftsarerotatably mounted upon the main frame ofthe machine in spacedparallel relation to the workframe. The two shafts are tied together torotate in synchronism such as by means of levers secured thereto and aninterconnecting link. The upper torque shaft is provided with a pair oflevers each of which .is connected to the upper corner portion oftheworkframe by rigid links while the lower shaft is similarly connected tothe lower corners of the frame.

, The frame is thus confined to move in the manner above defined. Itsweight, however, must be supported in a suitable manner and also it isimportant to cause movement of the frame to follow a substantiallystraight path in the cutting range. v The manner of producing thislinear movement constitutes a feature of the invention. Thesupport ofthe frame and its guidaims is accomplished by utilizing a system oflinks thereby avoiding the use of a slide mechanism which is unavoidablyinefiicient and furthermore its operation is notably adversely effectedby accumulated foreign manner such as chips and the like. In a linkagesystem all movement is achieved through pivot bearings having anexceedingly low friction coefficient and which also may readily bemaintained at maximum efficiency indefinitely by conventionallubricating methods independently of the presence of dust, chips andforeign matter.

One desirable means for accomplishing the result above outlined is tosupport the work frame upon a pair of relatively long links pivoted atthe ends of the work frame and arranged that the motion of the framewill be practically along a straight tangent line to the points ofattachment between the links and the workframe. Another mode ofsupportfor the frame is also presented wherein each end of the workframe is pivotally connected to the center of a horizontal lever whilethe outer ends of these levers arev pivoted to one end of a pair ofrelatively short equal links. The other ends of the link are pivotedupon fulcrum points symmetrically situated upon the main frame above andbelow the horizontal lev'eri "The'frame in this structure is caused ,to

move'in astr'aight path.

The frame supporting linkages above described coact with the torqueshafts to produce an accurate and uniform motion of the work frame butin addition to this fact the effort required to move the frame isreduced to a minimum due to the absence of excessive friction at allpoints in its supporting and guiding mechanism. This case of movementinsures a maximum .of.sensi-- tivity in the motion of the frame notattainable heretofore, and as a result of such sensitivity the workproduced is of a high degree of accuracy. Moreover the output of theapparatus may be increased because of the relatively rapid response inthe movement of the work frame which permits a substantial increase in.the operating peed of the lathe.

To present a better understanding of the invention, specific embodimentsthereof 'will now be described in connection with the accompanyingdrawings in which:

Fig. 1 is a front elevation of the apparatus.

Fig. 2 is an end elevation of the apparatus shown in Fig. 1.

Fig. 3 is an end elevation of a different embodiment of the invention.

Fig. 4 is a partial front elevation of the appa ratus shown in Fig. 3. vFig. 51s a partial front elevation of a modified'fcrm of the invention.v Fig. 6 is a diagrammatic illustrationshowing the relative position ofthe "last blocksand c'utter heads shown in Fig. 5.

The present invention basically provides a new type of precision threedimensional copying. lathe. The manner in which the relative movementsbetween the various elements. are obtained and columns I2 projectupwardly from the end portions of the bed and desirably are .tiedrigidly together by a cross bar I3. The bed ID is. provided with ways l4extending lengthwise thereof upon which a carriage I5 travels. In thefor-moi the invention illustrated, a model lliand a work piece I! areshown with their axes laterally separated and parallel. In this manner'aworkpiece having a leng h substantially equal to the full length of thelathe bed. may be produced, It is Within the scope of the presentinvention however, to provide the necessary supporting centers ordogswith their co-acting driving means to arrange a modeland work pieceinaxial alignment. Furthermore, two or more workpiecesmayjbe produced atthe same time as in the case'where a right.and"left shoe last is to bemanufactured. Such an apparatus will be described hereinafter.

In the embodiment illustrated in Figs..l and 2, a single carriage I5 isprovided with'a'cutter head I8 directly connected to the .shaftofa'motor I9,

the frame 20 of which is rigidly secured upon the carriage; The motorframe 20 may be provided-with an additional chamber 21 within whichanother motor maybe housed. The second motor may desirably be employedto perform a roughing cut simultaneously with the finishing outperformedby the head I8. The roughing cutter is not shown, but would be adaptedto 'be received upon the shaft 212shoWn projecting. from the cal form ofthe solid of revolution generated by the peripheral edges of the cutterblades upon the cutter head I8. Desirably the model wheel is adjustablealong a line transverse to the ways 114. To provide for this adjustmentthe model wheel is mounted upon a slide 24 received and guided in anupwardly extending portion 25 of thecasing 2 I. .The axes of the model.wheel and outer head are spaced vertically the same distance as theaxes of the model and workpiece.

The model and workpiece are driven simultaneously and in synchronism inany suitable manner. As shown herein the respective ends of the modeland workpiece are engaged by driving dogs .26 and ZTI whichare securedupon the inner ends of shafts-28 and 29 which are journaled in a headstock frame 38 rigidly secured to a movable work frame 3 I The otherends of the model and workpiece are supported by conventional tail stockcenters 32 and 33 situated in parallel alignment with the shafts 28 and29. The tail centers are axially adjustable within the tail stockffram'e34 by means of the rotatable handles 35 ..and 36 thereby to cause thetail stock centers to firmly engage the righthand extremities of themodel and'workpiece respectively thus .firmly supporting them. within.the. apparatus. The'tail stock frame (it desirably is adjustablelengthwise along the bars 3?! of the work frame .3I, to provide for thereception of workpieces of. various lengths.

The outer ends ofv the shafts 28 and 29 have secured thereon thegear's38 and 39.. These gears are driven by means of a small piniongear! secured'upon a drive shaft ll and meshing simultaneously with bothgears 38 and 39. The shaft M is journaled in the headstock frame 30'andprojects outward toreceive a driving pulley 42 secured thereon. Thepulley 42 is driven by a belt 43 which in turn is driven by a pulley Msecured upon a short shaft 45 journaled .in a bearing mounted on theleft hand column I12. The inner end of theshaft 45 has secured thereon apulley lawhich is driven from a pulley ll fixed upon a shaft 48, bymeans of a belt 49,. The shaft 48 is journaledat its ends inbearingsmounted on the columns I2 of the main frame. In addition to the pulley4! the shaft .48has secured thereon a threestep pulley 5i! and a drivingpulley 5| having a clutching "mechanism 52 'by means of which drivingpower may 'be transmitted to or disconnected from the model andworkpiece. When the turning of the work-piece is completed the frame 3!is pulled forward to a locked position away from the cutter. Thismovement operates a bar tifallFig. 2) which throws the clutch 52 out ofgear while the reverse movement connectsthe power to the model andwork-piece.

The pulley 5! is constantly driven from a pulley by a belt 54; Thepulley .53 is secured upona shaft journaled iii-bearings mounted uponthelegs .M of the main frame. The shaft 55. has thereon a pulley 5B-which in .turn is driven by a motor 51 from a pulley 5.8 fixed upon themotor'shaft. -The pulley 5 6 is drivennfrom a pulley 58 by means ofabelt 59. The driving motor 5'! may be mounted upon the frame in anydesired manner. A suitable means of mounting the motor is to secure-itupon a'pivoted bracket in such manner that its ownweight servestomaintain tension in the driving belt 59. Themodel and workpiece arethus rotated by power supplied from the motor 5 through the drivingmechanism above described.

Means are provided for. feedingtheycarriage I5: from power supplied bythe motor 51. -To

accomplish this end a belt 60 passing overv the pulley 50 also passesoverv a step pulley 6| fixed upon one end of a shaft 62 journaled in abearing 63 secured to a leg ll of the main frame. A pulley 64 has adriving connection with the pulley 65 secured upon a shaft .66 journaledat one end in a bearing 61 mounted upon a leg H. A worm 68 is securedupon the other end of the shaft 66 which engages and drives a worm gear69 rotatably mounted upon a stud shaft 10 fixed upon the main frame. qMotion of the worm gear 69 is transmitted to the carriage l5 by means ofa chain H. The chain is driven by a small sprocket 12 secured upon thegear wheel 69. The upper runof the chain 1! coming from the sprocket 12passes over an idler and tension adjusting sprocket 13 from where itextends to the sprocket I4- rotatably mounted upon a stud shaft 15secured uponthe main frame adjacent the end of the ways I4. The sprocketM is so situated that the upper run of the chain as it leaves thesprocket is in line with the point of attachment: of the chain to thecarriage [5. Any suitable means will serve to connect the chain to thecarriage. As shown'herein the carriage is provided with a projection 16(Fig. 2) extending forward from its base, upon the outer end of which ispivoted a connecting block '11. The two ends of the chain; are securedto opposite ends of the block 1 thereby transmitting 'movement of thechain to the carriage. The chain extends from the sprocket 14 to one endof the block 11 and from the other end of the block to another sprocketl8 rotatably mounted upon a stud shaft fixed upon the main frameadjacent the opposite end of the ways I4. From the sprocket 18 the chainextends back to the drive sprocket 12 thus completing the driving orfeeding system for the carriage. By shifting the belt 69 from one stepon the pulleys 50 and GI to another step thereon various rates of feedfor the car riage may be established.

In the operation of the machine the work frame 3| moves bodily parallelto the axes of the model and work-piece toward and from the model wheeland cutter head as the model wheel follows the contours of the model..The manner 'and means with which this motion of the work frame iscontrolled constitute an importantfeature of the invention. The frame 3|comprises the pair of bars 3'! which are substantially of the samelength as the width dimension of the bed ID. The bars are rigidlyconnected at their ends to a pair of end frame members 19. Desirably butnot essentially the members 19 are upwardly extended having theirextensions fastened to a pair. of brackets .80 which are also secured tothe upper bar 37. The brackets 80 provide additional rigidity to theframe 31 particularly against distortion. in its own flatwise plane. yThe weight of the frame 3! is supported by a pair of relatively longlinks 8! extending substantially vertically and pivoted at their lowerextremities respectively to the members 19 of the frame 3! adjacent itsend portions. The upper ends of the links are pivoted to the upperextremity of the columns I2 by means of brackets as shown. It isdesirable that the frame thus supported be braced against sidewisemotion. Any suitable means may be-utilized for this purpose. Onedesirable method is illustrated wherein a rigid bar 82 extends betweenthe columns I2. The end portions of the bar form the-pivot shaft for thelinks 8|. Stifi'ening bars 83 are rigidly anchoredat their upper endstoapoint adjacent the mid section of the bar 82 and extend downward atsubstantially a 45 angle and are rigidly anchored at their lower endsrespectively to the links 8|. Desirably means are provided to adjust thelength'of the links 8|. 'Any'suitable' means may be employedforthis-purpose. As illustrated the links 8| are composed of two sectionssecured to-' gether by a tie plate 84 which is slidably at tached tomove relatively lengthwise with respect to one or both of the linksections. Screws 85 are provided for locking the plate and sections ofthe links rigidly in adjusted position. To expedite fine adjustment ofthe length of the links adjusting devices 86 (Fig; 2) are providedconnecting the plate 84 and one section of the links 8|. The entireweight of the work frame 34 is thus supported by the links 8| which alsopermit bodily forward and backward motion thereof. I 4

The frame 31 must also be accurately and rigidly controlled in itsmovement to insure that its bodily motion forward and backward will takeplace without changing the angular position of the common plane in whichthe axes of the model and workpiece lie, that is, the various positionstaken by the frame are parallel to each other. A novel means is providedfor accomplishing this desired result is best shown in Fig. 2; A pair ofrigid torque shafts 81 and88 are rotatably mounted preferably at theback portion of the lathe with their axes lying in a plane parallel tothe 'plane of the axes of the model and work iece. The shaft 88 ismounted in bearings 89 fixed upon the lathe bed while the shaft 81 ismounted in bearings 90 rigidly securedto the backs of the columns l2.These bearings may be of the conventional cylindrical type butpreferably are ball or roller bearings. The shafts 81' and 88 should beof substantial diameter of the order of two and one-half to three inchesor more to provide maximum rigidity against toruue forces. a 1

The shaft 81 has rigidly fastened at its end portions a pair of arms 91extending substantially vertically upward, while the shaft '88 hassecured thereon a pair of similar vertical arms 92. A pair ofhorizontally positioned connecting links 93 and 94 are arranged inparallel alignment and pivot'ally connected to the outer endsrespectively of one of the pairs of arms 9| and 92. The other ends 'ofthe links are .pivoted to the upper and lower portion of the side framemember 19 of the w'orkframe 3|. Another pair of links 95 and 96 (Fig. 1)at the opposite side of the lathe are respectively pivoted upon theremaining arms 9| and 92 at one of their ends and at their other endsare pivoted to the other side frame member 19. All "four links areexactly equal in length and disposed parallel with respect to eachother.

The shaft 81 has secured thereto an arm '91 while th-e'shaft 88 hassecured thereto an arm 98. 'I'hearms 91 and 98 desirably projectrearwardly from their respective shafts and are positioned in parallelalignment. The outer ends of these arms are-pivotally tied together by arigid link 99 equal in length to the distance between the axes of theshafts 81 and 88. It will be apparent that the frame 3i is-thu-spositively guided in the manner required-The four corner portions are soconnected-together that they areforced to :move' in the same directionand with exactly the-same velocity. -A force tending to changetheangular eneegsrze 7 disposition of the frame :3I is directly met bythe highly rigid torque shafts 81 and 88 through theirinterconnecting:mechanism. In the operation of the'mechanismdt' will benoted that the torque shaft stabilizing means above described addssubstantially no'weight to the work'frame 3| and moreover only averysmall amountof inertia is introduced thereby 'to' the inherentinertia'in the work frame 3|. The design of the mechanism results in avery large reduction in the friction and "inertia encountered in aconventional type of copying lathe. The action ofthe'work frame is"therefore, extremely sensitive in its response tOr-thfi.varying'contours of the model which results in greater accuracy ofoperatiomand f-urthermore permits a higher speed of operation.

To: maintain the necessary contact pressure between the model andmOdel'wheel-any suitable means maybe employed. A satisfactoryarrangement 'isillustrated in the drawings wherein a short-arm I00 issecured to the shaft 88 and has secured thereto one end of a tensionspring IOI which is anchored at its other end :toa bracket m securedupon the machine base. The spring may desirably'be provided with meansfor adjusting itstension for example an eyebolt I03 passingthroughthe-bracket I02 and-provided with an adjusting not. The tension in thespring tends to rotate the shaft 88 which in turn acts through itsinterconnecting arms and links to move the work frame 3I-toward theright in Fig. 2 thus resilienily' urging themodel into engagement withthe model wheel. Slight rise and fall of the frame 3| due to the'arcuatepath of the pivotal connection 104a between'the lin-ks8I iandthe frame3| does not alter the precise repro'ducing'characteristicsof thelathesince the-torque shaft stabilizing means accurately maintains-exact parall'elism's and equal distances between the axesrespectivelyof the model andmodel wheel and the cutter head andworkpiece at all times. The modelrand workpiece rise and fall invery-small but equal distances during the machine operation so. thatthe'reproducing accuracy ofthe lathe remains unchanged for allworking'positions of the frame 31.

1 In-*the-operation of the-apparatus shown in Figs;- 1 and 2, the frame3I=is supported onnthe mainframe by the relatively long links 81 pivotedtdthebo'ttom of the frame 3L -The==lin1ksare slightly back of a .planethrough the axes of the modeland workpiece so that in the cutting rangeof movement of-the 'frame 3 I.,-ea.ch pivot ofthe links thereto movesforward and backinsubstant-ially-a straight line. The lower pivot pointsof thefllinks 8iv may form a slight arc, but this is almostniegligiblein the cuttingrange. Inyany case,- the frame :must move bodily forwardand backward with respect to the main frame and the model-wheeland-cutters, because'of the arrangement-ofthe links-03 and 94 attachedto the four corners'xof'the flame. Si-nce the? links 93- and 04 areconnected in a parallel motion "system; the fOTllrYCOIIlGF-sfif theframe 3|" must move at the same time 'in thesame :directi'on'and to thesame extent. Therefore; regardless of any slight arc atzthe lower endsof the links 81, the :fram'efil in any given position is always parallelto any other given position it may assume.

. Inthe modified form of the invention is shown inrFigs; 3 and 4 themainframe, the means for rotating the model and workpiece and the meanstor-feeding the carriage ares'imila'r inzconstructi'on to'thecorresponding 'ele'ments'abov'e' described in connection with the otherform of the invention. The main difference between the two forms of theinvention lies in the means employed tosupport the weight of the workframe 3|. 1 The links 81 described in-connection with the other form ofthe invention are eliminated in the modified form to be described. Theweight of the frame 31 is supported by a .pair of horizontal floatinglevers I04 pivotally connected at their mid points to the lower portionof I the side brackets I9 of the frame SL The outer ends of the leversI04 are pivotallyconnected to'pair's of substantially verticalllinks I05and I06 which in turn are pivotallyconnected to fulcrum points upon themainframe. The links I05 are pivoted to brackets I01 rigidly securedtothe columns I08 and I09 above the lever I04. The levers I06 arepivotally connected 'to plates IIO.rigidly fas tened to the endfaces ofthe lathe bed I0 at poin'tsbelow the lever I04.

a Tozi-mprove the endwise-stability'of the above described guidingmechanism'it may be desirable to tie together the pair oflinks I06. Asuitable means for accomplishing-this'result is to'provide a relativelyrigid bar III fixed between the links I00. "This bar may be 'castintegrally therewith or may be rigidly secured thereto. 'T-hismodifiedform of suspending mechanism for the work frame *3I 'is extremelysensitive in operationand provides true straight line forwardand-"backward motions of the work. frame 3|; The! torque shafts 87 and88 and" theirintercomiecting arms and links function in the same manneras hereinbefore described in connection with Figs. 1 and 2.

It'will 'benoted that the columns I08 and I09 differ somewhat instructure'fr-om the columns I2 described in connection with Figs. 1 and2. The column I08 isrelatively short and its upper end serves only tosupport the right bearing for the shaft 48 while the upper end of thecolumn I09 serves'only to support the'beari-ng for the shaft 45, therebeing no necessity for supporting the upper end of weight supportinglinks 0| since in this form of the invention other-means is providedtherefor.

The operation of the apparatus shown in Figs. 3"and 4 is somewhatsimilar to that described above in connection with Figs. 1 and2,'although the work frame issupported by a substantially differentmeans. In these figures, the same parallel motion arrangement is used asthat used in Figs. 1' and '2. The work frame supporting means, includingthe symmetrically arranged links I05, I00 :and the cross links I04,provide a novel arrangement by which thepivot point of the frametothelinks' I04." moves in a straight line. Thisstrai'g-ht line motionis provided because the arc formed by the movement of the link I05 isdirectly offset Edythe-movement of the link I06. The backward andforward movement of'the work frame in the cutting zone, in an apparatusof this type, is not very great, and the'supporting means shown in Figs;3 and 4 includes a novel pivoted arrangement for providing a straightline motion for the work'frame. The workframe shown in Fig. 5*of thedrawings is supported and operated similar to that of Figs. 3 and 4.

' Fig. 5 of the drawings illustrates another application of theprinciples of the invention wherein the elements are arranged to producea pair of lasts for right and-left shoes'simultaneously. The. drawing ispartially. diagrammatic and illustrates only one of" the many possiblearrangements ofparts. Only the work frame II2 carrying the model H3 andthetwo'las't blocks II I secured thereto a block driving dogIZII.

and cutter head carriage. The work frame H2 is provided with'thesam'ehead stock 38 illustrated in Fig. 1, the two spindles of whichare driven by the pulley 42 over which the belt 43 passes. The spindle29 is provided with a dog IIB for engaging the heel of the model H3. Thetoe of the model is supported by a toe dog I I! having axial adjustmentin a tail stock I I8 rigidly secured'to the cross bars 31.

The'upper' spindle 28 is extended and has a bearing in a, head stock II9 rigidly secured to the cross bars 31. The elongated spindle 28 hasThe spindle 28 is also provided with a gear I2I secured rigidly thereto.The gear I2I meshes with the gear I22 of the same diameter mounted upona spindle I23 journaled inthe head stock H9. The spindle I 23 hassecured thereto a dog I24. The dogs I and I24 engage and drive lastblocks H4 and I I5 respectively which'are supported at their oppositeends by dogs I25 and I26 axially adjustable in the tail stock. securedto the cross bar 31 and which is or may be identical to the tail stockshown in Fig. 1. The model H3 and the block II 4 are thus driven in thesame direction while the block II5 is driven in the opposite directionthroughout the turning operation thus producing a right and a left last.

-'A conventional model wheel carriage I2! is adapted to travel'upon theways I4 upon the bed I0 and has mounted thereon a model wheel I28 whichengages the model II3.- Another carriage I29 also moves upon the ways I4and has mounted thereon a pair of driven cutter heads I30 and I3Imounted upon the shafts of the motors I32 and I33 which are rigidlysecured upon the carriage I29. The axes of the cutters are spaced apartthe same distance as the axes of spindles 28 and I23 and are alsosituated in a plane parallel to the plane upon which the axes of theshafts 28 and I23 lie.

Desirably the two carriages are connected to gether by a conventionalgrading mechanism I34 by means of which various sizes of lasts may beproduced from a single model. The work frame II 2 in this form of theinvention is supported and guided in its motion in the same manner asthat of the work frame described in connection with Fig. 3 and Fig. 4 ofthe drawings.

The operation of this form of the invention is obvious. Due to theprecision of movement of the frame II 2 a perfect pair of lasts may beproduced simultaneously from the model H3. The usual fan board mechanismand other conventional adjustments not shown may be provided.

We claim:

1. In 3, copying lathe includin a main frame and a work holding framesupported thereon having means for holding and rotating a model and workpiece, the improvement which comprises means for supporting said workframe including a pair of relatively long spaced links pivoted at oneend upon said main frame and at their other ends upon said work frame,means for guiding said work frame including a pair of spaced paralleltorque shafts rotatably mounted upon said main frame and disposedparallel to said work frame, means connecting said shafts to rotate themin synchronism, lateral extensions upon said shafts, and rigid connectinmembers interconnecting said lateral extensions with said work frameacting to constrain said work frame to move with a motion characterizedas bodily movement at substantially a right angle to its generalflatwise plane and without angular displacement from that plane.

2. In acopying lathe including a main frame and a'work holding framehaving means to support and drive a model and a work piece upon parallelaxes, the improvement which comprises means to support the Weight ofsaid work holding frame and permit it to move toward and from a portionof the main frame, means to control the movement of said work frame asit moves toward and from said main frame'in eludin at least tworelatively long spaced torque shafts rotatably mounted on said mainframe, extending parallel to and for substantially the .full length ofsaid. work frame, positive, mechanical means to causesynchronized'rotation of said torque shafts, at least two levers on eachof said shafts extending laterally outward therefrom, and link membersconnecting the outer ends of said levers to said workframe thereby tocause said frame to move with a motion characterized as bodily movementtransversely of its general flatwise plane and without angulardisplacement from that plane;

3. In a copying lathe including a mainframe and a work sup-porting framehaving means to support and rotate a model and work piece thereon, theimprovement which comprisespivoted means extending between said workframe and said main frame acting to support the weight of said workframe and permit movement thereof toward and from a portion of the mainframe, a pair of vertically spaced parallel torque members rotatablymounted on said main frame, means to cause them to rotate insynchronism, arms of equal length extending upwardly from said torquemembers and fixed thereto, link members connecting the ends of said armsto said work frame at substantially spaced points to maintain said workframe parallel to the plane of said torque members.

4. In a copying lathe including a main frame and a Work holding framehaving means to support and rot-ate a model and work piece therein, theimprovement which comprises at least two supporting levers pivotallyfastened to said work frame at their mid-point upon fulcrum pointslaterally separated a substantial distance upon said work frame, pairsof links of equal length pivot-ally connected at one of their ends tothe outer ends of said supporting levers and pivoted at their other endsupon said main frame at points symmetrically disposed on opposite sidesof said levers whereby the pivot points between said levers and saidwork frame are caused to travel in a straight line, means to guide saidwork frame to travel with a motion characterized as bodily movementtransversely of its general flatwise plane and without angulardisplacement from that plane, said means including a pair of torqueshafts having means to cause them to rotate in synchronism, and meansinterconnecting said torque shaft and said work frame operable tocontrol the forward and backward motion of said work frame.

5. In a copying lathe including a main frame and a work holding framehaving means to support and rotate a model and a work piece on separateaxes, the improvement which comprises pivot means to support said workframe and permit movement thereof, means for guiding said work frame ina forward and backward motion ineluding a pairof. parallel torqueshafts-rotatably 6. In. a copying lathe including ,a main frame andajwork holding frame having means to support and rotatea model, andiworkpiece therein on separate parallel axes, the irhprovementWhich comprisesat least two supporting levers pivotally fastened to, said work frame attheir mid-point uponfulcrum points laterally separated a.-subs'tantialdistance upon said work'framapairs of links of equal length pivotallyconnected. at one vof theiriends to. the outer ends of said supportinglevers and, pivoted at'their otherendsuponsaid main, frame. at pointssymmetrically disposed on opposite ,sides of said levers whereby thepivot points between said levers and. sa'idrwork frame are caused to-travel in a straight line, and a par- 'allel motion guiding meansmounted on saidmain frame and connected to said, work holdin frame bysubstantially spaced laterally extending. rigid linkmembers attached:tol each end of the work holdingiframe by end attachments, the linkmembers',having their other ends mechanically in terconnected, forconcordant substantially axial movement, said parallelmotion guidingmeans being adapted to guide said work fr'ameinit-s movel2 mentsandarrangcd itoirestrict said: work holdin frame to substantiallya-straight line Joodymotion at a right angle tothe plan-e of theworkholding frame in the rangeioflthe cutting. operation ofthe lathe.

'1 In acopying lathe as definedby claimsB-in which .means is attached toone of said torque members for causing rotation thereof and for urgingthe work-frame toward a i=portion of the main frame. 7

GEORGE-CLAUSING. CHARLES E.

B EFEIHSNCES CITED,

Thejfollowihg references are of recordin: the file of this patent 2UNITED STATES PATENTS Number.- Name Date 161,831 Chopin; Augw, 1882460,699 Autenrieth. A Oct. 16., 1891 6;!356 Neudortfv June 11 1907968,672 Loewer e Aug: 30, 1910 1,407,727 1 Buck 1;; Feb: 28',.19221,684,072;-5; Reed. Sept..11,v1928 1172-73996 Ryan 7' Sept; 19,19291,733,207 Ryan et al. 4L1 Qct.,29; 1929 FOREIGN PATENTS 1 Number CountryDate- 70,792 Sweden-, .Apr.w4, 1928 288,301 5. Great -B. itai1'-L'-:Jan; '17, 1929

